Diagnostic Procedure With Diagnostic Trouble Code (Dtc) - Subaru Legacy 2002 Service Manual

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

No.
1 CHECK CONDITION OF CRANKSHAFT
POSITION SENSOR INSTALLATION.
2 CHECK CRANKSHAFT POSITION SENSOR.
1) Remove crankshaft position sensor.
2) Measure resistance between connector
terminals of crankshaft position sensor.
Terminals
No. 1 — No. 2:
3 CHECK HARNESS BETWEEN ECM AND
CRANKSHAFT POSITION SENSOR CON-
NECTOR.
1) Connect connector to crankshaft position
sensor.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
crankshaft position sensor connector and
ECM.
Connector & terminal
(B135) No. 8 — (B135) No. 2 (With
immobilizer)
(B135) No. 8 — (B135) No. 1 (Without
immobilizer)
4 CHECK HARNESS BETWEEN ECM AND
CRANKSHAFT POSITION SENSOR CON-
NECTOR.
Measure resistance of harness between ECM
connector and chassis ground.
Connector & terminal
(B135) No. 8 — Chassis ground:
5 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF.
2) Set the positive (+) probe and ground lead
of oscilloscope at ECM connector terminals.
3) Measure voltage indicated on oscilloscope
while cranking the engine.
Connector & terminal
(B135) No. 2 (+) — (B135) No. 8 (−):
(With immobilizer)
(B135) No. 1 (+) — (B135) No. 8 (−):
(Without immobilizer)
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
7 CHECK ECM.
1) Connect all connectors.
2) Erase the memory. <Ref. to EN(w/oOBD)-
30, OPERATION, Clear Memory Mode.>
3) Perform inspection mode. <Ref. to EN(w/
oOBD)-28, OPERATION, Inspection Mode.>
4) Read out the trouble code. <Ref. to EN(w/
oOBD)-26, OPERATION, Read Diagnostic
Trouble Code (DTC).>
8 CHECK ANY OTHER TROUBLE CODES
APPEARANCE.
Step
Are the crankshaft position
sensor installing bolts tight-
ened securely?
Is the resistance between 1
and 4 kΩ?
Is the resistance between 1
and 5 kΩ?
Is the resistance less than
10 Ω?
Is the voltage more than
400 mV?
Is there poor contact in
ECM connector?
Is the same trouble code
as in the current diagnosis
still being output?
Are other trouble codes
being output?
EN(w/oOBD)-69
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Repair ground
short circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector.
Go to step 6.
Repair poor con-
tact in ECM con-
nector.
Replace genera-
tor.
Proceed with the
diagnosis corre-
sponding to the
trouble code.
Engine (Diagnostics)
No
Tighten crankshaft
position sensor
installing bolts
securely.
Replace crank-
shaft position sen-
sor.
Repair harness
and connector.
NOTE:
In this case,
repair the follow-
ing:
¼ Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
¼ Poor contact in
coupling connec-
tor (B21)
Go to step 5.
Replace crank-
shaft position sen-
sor.
Go to step 7.
Go to step 8.
A temporary poor
contact.